Operating device for lamps with a regulated SEPIC converter

Abstract

The invention relates to a novel operating device for lamps, in particular low-pressure gas discharge lamps, in which a SEPIC converter is used for charging a storage transistor from an AC voltage supply. In this case, the SEPIC converter is regulated to an output quantity as regulated variable, its operating frequency being altered. Preferably, only the switch-on time and not the switch-off time of the switching transistor of the SEPIC converter is altered in this case.

What is claimed is:  
     
       1. Electronic operating device for lamps, which is designed for supply with AC voltage and has: 
       a storage capacitor (C 2 ),  
       a SEPIC converter (L 1 , L 2 , C 1 , T 1 , D 1 ) for charging the storage capacitor (C 2 ) from the AC voltage to a DC voltage in the case of an operating device current consumption which is essentially tracked to the AC voltage waveform with an operating frequency, and  
       a regulating circuit (RS) for regulating the SEPIC converter to an output quantity,  
       characterized in that the regulating circuit (RS) alters the operating frequency of the SEPIC converter (L 1 , L 2 , C 1 , T 1 , D 1 ) during regulation. 
     
     
       2. The operating device as claimed in  claim 1 , in which the switch-on time (dTs) of a switching transistor (T 1 ) of the SEPIC converter (L 1 , L 2 , C 1 , T 1 , D 1 ) which occurs in the periods of the operating frequency is altered during the regulation of the SEPIC converter (L 1 , L 2 , C 1 , T 1 , D 1 ). 
     
     
       3. The operating device as claimed in  claim 2 , in which the switch-off time (d'T s ) of a switching transistor (T 1 ) of the SEPIC converter (L 1 , L 2 , C 1 , T 1 , D 1 ) which occurs in the periods (T s ) of the operating frequency remains constant during the regulation of the SEPIC converter (L 1 , L 2 , C 1 , T 1 , D 1 ). 
     
     
       4. The operating device as claimed in  claim 3 , which is designed for quasi-transient operation of the SEPIC converter (L 1 , L 2 , C 1 , T 1 , D 1 ) with currentless times—occurring in the periods (T s ) of the operating frequency—of in each case at most 10 % of the period duration (T s ). 
     
     
       5. The operating device as claimed in  claim 3 , in which the regulating circuit (RS) is a digital circuit and the operating frequency of the SEPIC converter (L 1 , L 2 , C 1 , T 1 , D 1 ) is regulated in time-discrete fashion. 
     
     
       6. The operating device as claimed in  claim 5 , in which the regulating intervals of the time-discrete regulation are at least as long as half the period of the AC voltage. 
     
     
       7. The operating device as claimed in  claim 3 , which is suitable for a plurality of lamp types and has a programmable control circuit with a memory with operating parameters of the lamp types, the programmable control circuit concomitantly comprising the regulating circuit for regulating the SEPIC converter. 
     
     
       8. The operating device as claimed in  claim 7 , which is designed in such a way that an automatic initial setting to individual parameters of the mounted components (L 1 , L 2 , C 1 , C 2 , T 1 , D 1 ) is effected at the beginning of the operation. 
     
     
       9. The operating device as claimed in  claim 7 , having an oscillator, which is controlled by the programmable control circuit and is supplied with DC voltage power by the storage capacitor (C 2 ). 
     
     
       10. The operating device as claimed in  claim 1 , which is designed for quasi-transient operation of the SEPIC converter (L 1 , L 2 , C 1 , T 1 , D 1 ) with currentless times—occurring in the periods (T s ) of the operating frequency—of in each case at most 10 % of the period duration (T s ). 
     
     
       11. The operating device as claimed in  claim 1 , in which the regulating circuit (RS) is a digital circuit and the operating frequency of the SEPIC converter (L 1 , L 2 , C 1 , T 1 , D 1 ) is regulated in time-discrete fashion. 
     
     
       12. The operating device as claimed in  claim 4 , in which the regulating intervals of the time-discrete regulation are at least as long as half the period of the AC voltage. 
     
     
       13. The operating device as claimed in  claim 1 , which is suitable for a plurality of lamp types and has a programmable control circuit with a memory with operating parameters of the lamp types, the programmable control circuit concomitantly comprising the regulating circuit for regulating the SEPIC converter. 
     
     
       14. The operating device as claimed in  claim 13 , which is designed in such a way that an automatic initial setting to individual parameters of the mounted components (L 1 , L 2 , C 1 , C 2 , T 1 , D 1 ) is effected at the beginning of the operation. 
     
     
       15. The operating device as claimed in  claim 13 , having an oscillator, which is controlled by the programmable control circuit and is supplied with DC voltage power by the storage capacitor (C 2 ). 
     
     
       16. The operating device as claimed in  claim 1 , which is designed for supplying a low-pressure gas discharge lamp.